Greater Plantain (Plantago major) and Infection (general): evidence and sources

PURPOSE: To determine the in vitro effectiveness of Plantago major extract, along with two of its active components, aucubin and baicalein, on the inhibition of Candida albicans growth, biofilm formation, metabolic activity, and cell surface hydrophobicity. MATERIALS AND METHODS: Twofold dilutions of P. major, aucubin, and baicalein were used to determine the minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC), and the minimum biofilm inhibitory concentration (MBIC) of each solution. Separately, twofold dilutions of P. major, aucubin, and baicalein were used to determine the metabolic activity of established C. albicans biofilm using a 2,3-bis (2- methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-carboxanilide reduction assay. Twofold dilutions of P. major, aucubin, and baicalein were used to determine the cell surface hydrophobicity of treated C. albicans biofilm by a two-phase assay using hexadecane. The hydrophobicity percentage of the cell surface was then calculated. A mixed-model ANOVA test was used for intergroup comparisons. RESULTS: The MICs of P. major extract (diluted 1:2 to 1:8), aucubin (61 to 244 μg/ml), and baicalein (0.0063 to 100 μg/ml) on the total growth of C. albicans were noticeable at their highest concentrations, and the inhibition was dose dependent. The MFC was evaluated after 48 hours of incubation, and aucubin (244 μg/ml) exhibited a strong fungicidal activity at its highest concentration against C. albicans growth. The MBIC indicated no growth or reduced growth of C. albicans biofilm at the highest concentrations of aucubin (61 to 244 μg/ml) and baicalein (25 to 100 μg/ml). Similarly, the effects of these reagents on C. albicans biofilm metabolic activity and hydrophobicity demonstrated high effectiveness at their highest concentrations. CONCLUSION: P. major extract, aucubin, and baicalein caused a dose-dependent reduction on the total growth, biofilm formation, metabolic activity, and cell surface hydrophobicity of C. albicans. This demonstrates their effectiveness as antifungals and suggests their promising potential use as solutions for C. albicans biofilm-related infections.

Introduction The use of herbal extracts is increasing because of the increase in bacterial resistance to conventional antibiotics. Plantago major is frequently used in traditional medicine because of its medicinal properties. The aim of the current study was to assess the antibacterial efficacy of an ethanolic extract of P. major leaves against Pseudomonas aeruginosa isolated from burn infections. Methodology One hundred and twenty burn samples were collected from hospitalized patients at the Burn Hospital in Duhok city. The bacterium was identified using Gram stain, colony morphology, biochemical tests and selective differential media. Antibacterial activity of P. major leaves was assessed by using an ethanolic extract in serial dilutions of 100, 75, 50, 25, and 10 % and disc diffusion assay. Antibiotic susceptibility testing was also performed by disk diffusion using Muller-Hinton agar medium. Results Different concentrations of the ethanolic extract of P. major leaves exhibited different zones of inhibition against P. aeruginosa from 9.93 mm to 22.18 mm in diameter. The inhibition zone increased as the concentration of the extract increased. The 100% ethanolic extract had the greatest inhibitory effect, inhibiting bacteria in the zone of 22.18 mm diameter. This bacterium showed a high level of resistance to the antibiotics used. Conclusions This study demonstrated that herbal extracts could be used as a combination therapy with antibiotics and chemical drugs in the elimination of bacterial growth. Further investigations and future experiments, need to be carried out before recommending use of herbal extracts.

Since ancient times, many scientists and doctors have used various herbs to treat diseases. Conventional drugs often have side effects, and pathogens are becoming resistant to these types of drugs. In such circumstances, the study of traditional medicinal plants is an effective and logical strategy for finding new herbal medicines. One such herb is Plantago major, a perennial plant in the Plantaginaceae family that is found throughout the world. The Plantago major plant has been used as a medicine for the treatment of various diseases. Studies have shown that plant extracts of Plantago major exhibit antimicrobial, antiviral, and anti-inflammatory effects, and have wound-healing properties. This review collects and presents the results of various studies of Plantago major plant extracts with antimicrobial, antiviral, antifungal, anti-inflammatory, and wound-healing properties, which demonstrate a wide range of therapeutic possibilities of Plantago major plant extracts and have a huge potential for use as a medicinal raw material.

Plantago major linn. and P. asiatica Linn. (Plantaginaceae) are commonly used as folk medicine in Taiwan for treating infectious diseases related to the respiratory, urinary and digestive tracts. In this study, we investigated the antiviral, cytotoxic and immunomodulatory activities of hot water extracts of these two species in vitro on a series of viruses, namely herpesviruses (HSV-1 and HSV-2), adenoviruses (ADV-3, ADV-8 and ADV-11), and on various human leukemia, lymphoma and carcinoma cells with XTT, BrdU and IFN-gamma kits. Results showed that hot water extract of P. asiatica possessed significant inhibitory activity on the proliferation of lymphoma (U937) and carcinoma (bladder, bone, cervix, kidney, lung and stomach) cells and on viral infection (HSV-2 and ADV-11). P. major and P. asiatica both exhibited dual effects of immunodulatory activity, enhancing lymphocyte proliferation and secretion of interferon-gamma at low concentrations ( 50 microg/ml). The present study concludes that hot water extracts of P. major and P. asiatica possess abroad-spectrum of antileukemia, anticarcinoma and antiviral activities, as well as activities which modulate cell-mediated immunity. Further investigations to elucidate the active component(s) of P. asiatica and P. major and to evaluate their clinical application are warranted.

Advances in organic chemistry, biochemistry, biotechnology and molecular virology have made it possible to synthesize a large number of antiviral drugs belonging to different pharmacological groups. However, one but significant disadvantage of these drugs is their significant toxicity. Therefore, along with the screening of new drugs among synthetic compounds, scientists are actively conducting research on antiviral agents of natural origin. Natural products with antiviral properties have advantages over synthetic compounds due to their low toxicity, minimal side effects, and mild action by various mechanisms. The aim of the study was to investigate the antiviral properties of aqueous-alcoholic extracts of plantain leaves (Plantago major L. and Plantago lanceolata L.), wild and garden raspberry leaves (Rubus idaeus L.) and their fermented variants on the model of human adenoviruses (HAdV3, HAdV5 and HAdV7). Methods. Determination of cytotoxicity and antiviral action of extracts was performed by standard methods using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). The titer of the virus, synthesized in the presence of drugs was determined by the end of dilution of the virus, which causes 50% development of the cytopathic effect of the virus on cells (СPE). Neoflazid was used as a reference drug. Neoflazid, developed by Ecopharm (Ukraine), it contains carboxylic acids and flavonoid glycosides isolated from wild cereals Deschampsia caespitosa L. (pike, turf) and Calamagrostis epigeios L. (dugout). All studies were performed in three replicates; the number of parallel determinations was 3–4. Calculated mean values, standard deviation, mean error. Differences in averages were considered significant at p3 mg/mL. For extracts from the leaves of Plantago lanceolata L. and Rubus idaeus L. (garden) and their fermented variants, the toxicity was slightly higher (CC50=1.5 mg/mL). Extracts showed either a slight antiviral effect or its complete absence when used in a prophylactic regimen. We observed effective inhibition of reproduction of adenoviruses, when using extracts after adsorption of viruses. Extract of plantain leaves in concentrations of 0.06–3 mg/mL inhibited the reproduction of HAdV5 by 68–83% and inhibited the reproduction of HAdV3 and HAdV7 in concentration 3 mg/mL by 55% and 11%, respectively. Extract of Rubus idaeus L. (wild) leaves in the concentration range of 0.06–3 mg/mL inhibited the reproduction of HAdV5 by 65–89%, HAdV3 by 41–84% and HAdV7 by 22–59%. The maximum inhibition of reproduction of HAdV3 by 34% is shown for the extract from the leaves of Rubus idaeus L. (garden) at a concentration of 0.38 mg/mL, the reproduction of other viruses was suppressed by only 4–22%. It has been shown that the extracts of plantain and wild raspberry significantly affected the infectivity of viral offspring. Extract of plantain at a concentration of 3 mg/mL inhibited the reproduction of HAdV5 by 1.5 lg, fermented extract of plantain – by 1 lg. Fermented plantain extract at a concentration of 0.06 mg/mL inhibited the formation of new viral offspring, the index of reproductive inhibition (IRI) was 1.6 lg. Both fermented and unfermented Rubus idaeus L. (wild) extract had almost the same antiviral activity, IRI was 1.45 lg – 1.6 lg. Extracts of plantain and raspberry, regardless of the concentrations used, effectively inhibited the formation of infectious offspring of the HAdV3. The maximum IRI was 1.44 lg for plantain extract and 1.5 lg for fermented plantain extract. Both raspberry extracts (fermented and non-fermented) inhibited the synthesis of adenovirus serotype 3 by 1.46 – 1.54 lg. The drug Neoflazid completely inhibited the formation of infectious adenovirus at a concentration of 7.1 μg/mL. Virulicidal activity of all extracts against human adenoviruses 3, 5 and 7 serotypes was not detected. We found different antiviral activity of extracts of wild and garden raspberry leaves; we can assume that the flavonoid composition of the extracts plays an important role in their activity. Conclusions. Our new data on a wide range of anti-adenoviral activity of plantain and raspberry extracts is a prerequisite for further studies of the properties of individual components of extracts, in order to create an anti-adenoviral drug and recommendations for its pharmacological use.